A current self-limited protective device studied by LF-noise measurements

Electrical properties of composite carbon-epoxy material may lead to many applications in electronics systems, in particular as protective devices. Conduction mechanisms in such components are investigated on the basis of first order characteristics (I-V curves) and of excess low frequency noise measurements. The great influence of thermal effects on the electrical characteristics are highlighted by complementary studies using IR thermography. A first attempt is made to test the reliability of these devices and to determine the failure modes by the comparison of the excess noise before and after high stress cycles.